﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace 图片处理测试
{/// <summary>
/// 调用StringComputeInit来对比字符串，需要str1
/// 和str2 返回数字
/// </summary>
    class StringCompute
    {

     
            #region 私有变量
            /// <summary>
            /// 字符串1
            /// </summary>
            private char[] _ArrChar1;
            /// <summary>
            /// 字符串2
            /// </summary>
            private char[] _ArrChar2;
            /// <summary>
            /// 统计结果
            /// </summary>
            private Result _Result;
            /// <summary>
            /// 开始时间
            /// </summary>
            private DateTime _BeginTime;
            /// <summary>
            /// 结束时间
            /// </summary>
            private DateTime _EndTime;
            /// <summary>
            /// 计算次数
            /// </summary>
            private int _ComputeTimes;
            /// <summary>
            /// 算法矩阵
            /// </summary>
            private int[,] _Matrix;
            /// <summary>
            /// 矩阵列数
            /// </summary>
            private int _Column;
            /// <summary>
            /// 矩阵行数
            /// </summary>
            private int _Row;
            #endregion
            #region 属性
            public Result ComputeResult
            {
                get { return _Result; }
            }
            #endregion
            #region 构造函数
            public StringCompute(string str1, string str2)
            {
                this.StringComputeInit(str1, str2);
            }
            public StringCompute()
            {
            }
            #endregion
            #region 算法实现
            /// <summary>
            /// 初始化算法基本信息
            /// </summary>
            /// <param name="str1">字符串1</param>
            /// <param name="str2">字符串2</param>
            private void StringComputeInit(string str1, string str2)
            {
                _ArrChar1 = str1.ToCharArray();
                _ArrChar2 = str2.ToCharArray();
                _Result = new Result();
                _ComputeTimes = 0;
                _Row = _ArrChar1.Length + 1;
                _Column = _ArrChar2.Length + 1;
                _Matrix = new int[_Row, _Column];
            }
            /// <summary>
            /// 计算相似度
            /// </summary>
            public void Compute()
            {
                //开始时间
                _BeginTime = DateTime.Now;
                //初始化矩阵的第一行和第一列
                this.InitMatrix();
                int intCost = 0;
                for (int i = 1; i < _Row; i++)
                {
                    for (int j = 1; j < _Column; j++)
                    {
                        if (_ArrChar1[i - 1] == _ArrChar2[j - 1])
                        {
                            intCost = 0;
                        }
                        else
                        {
                            intCost = 1;
                        }
                        //关键步骤，计算当前位置值为左边+1、上面+1、左上角+intCost中的最小值 
                        //循环遍历到最后_Matrix[_Row - 1, _Column - 1]即为两个字符串的距离
                        _Matrix[i, j] = this.Minimum(_Matrix[i - 1, j] + 1, _Matrix[i, j - 1] + 1, _Matrix[i - 1, j - 1] + intCost);
                        _ComputeTimes++;
                    }
                }
                //结束时间
                _EndTime = DateTime.Now;
                //相似率 移动次数小于最长的字符串长度的20%算同一题
                int intLength = _Row > _Column ? _Row : _Column;

                _Result.Rate = (1 - (decimal)_Matrix[_Row - 1, _Column - 1] / intLength);
                _Result.UseTime = (_EndTime - _BeginTime).ToString();
                _Result.ComputeTimes = _ComputeTimes.ToString();
                _Result.Difference = _Matrix[_Row - 1, _Column - 1];
            }


            /// <summary>
            /// 计算相似度（不记录比较时间）
            /// </summary>
            public void SpeedyCompute()
            {
                //开始时间
                //_BeginTime = DateTime.Now;
                //初始化矩阵的第一行和第一列
                this.InitMatrix();
                int intCost = 0;
                for (int i = 1; i < _Row; i++)
                {
                    for (int j = 1; j < _Column; j++)
                    {
                        if (_ArrChar1[i - 1] == _ArrChar2[j - 1])
                        {
                            intCost = 0;
                        }
                        else
                        {
                            intCost = 1;
                        }
                        //关键步骤，计算当前位置值为左边+1、上面+1、左上角+intCost中的最小值 
                        //循环遍历到最后_Matrix[_Row - 1, _Column - 1]即为两个字符串的距离
                        _Matrix[i, j] = this.Minimum(_Matrix[i - 1, j] + 1, _Matrix[i, j - 1] + 1, _Matrix[i - 1, j - 1] + intCost);
                        _ComputeTimes++;
                    }
                }
                //结束时间
                //_EndTime = DateTime.Now;
                //相似率 移动次数小于最长的字符串长度的20%算同一题
                int intLength = _Row > _Column ? _Row : _Column;

                _Result.Rate = (1 - (decimal)_Matrix[_Row - 1, _Column - 1] / intLength);
                // _Result.UseTime = (_EndTime - _BeginTime).ToString();
                _Result.ComputeTimes = _ComputeTimes.ToString();
                _Result.Difference = _Matrix[_Row - 1, _Column - 1];
            }
            /// <summary>
            /// 计算相似度
            /// </summary>
            /// <param name="str1">字符串1</param>
            /// <param name="str2">字符串2</param>
            public void Compute(string str1, string str2)
            {
                this.StringComputeInit(str1, str2);
                this.Compute();
            }

            /// <summary>
            /// 计算相似度
            /// </summary>
            /// <param name="str1">字符串1</param>
            /// <param name="str2">字符串2</param>
            public void SpeedyCompute(string str1, string str2)
            {
                this.StringComputeInit(str1, str2);
                this.SpeedyCompute();
            }
            /// <summary>
            /// 初始化矩阵的第一行和第一列
            /// </summary>
            private void InitMatrix()
            {
                for (int i = 0; i < _Column; i++)
                {
                    _Matrix[0, i] = i;
                }
                for (int i = 0; i < _Row; i++)
                {
                    _Matrix[i, 0] = i;
                }
            }
            /// <summary>
            /// 取三个数中的最小值
            /// </summary>
            /// <param name="First"></param>
            /// <param name="Second"></param>
            /// <param name="Third"></param>
            /// <returns></returns>
            private int Minimum(int First, int Second, int Third)
            {
                int intMin = First;
                if (Second < intMin)
                {
                    intMin = Second;
                }
                if (Third < intMin)
                {
                    intMin = Third;
                }
                return intMin;
            }
            #endregion
        }
        /// <summary>
        /// 计算结果
        /// </summary>
        public struct Result
        {
            /// <summary>
            /// 相似度
            /// </summary>
            public decimal Rate;
            /// <summary>
            /// 对比次数
            /// </summary>
            public string ComputeTimes;
            /// <summary>
            /// 使用时间
            /// </summary>
            public string UseTime;
            /// <summary>
            /// 差异
            /// </summary>
            public int Difference;
        }
    }
